Solid state starting and operating system for a constant combustion engine

ABSTRACT

Solid state NOR gates are connected into a logic circuit for controlling, starting and operating a gas turbine engine. The logic circuit requires less electric current and reduces switch costs while increasing overall reliability and life.

United States Patent 1 Fenton 51 Oct. 29, 1974 SOLID STATE STARTING AND OPERATING SYSTEM FOR A CONSTANT COMBUSTION ENGINE [75] Inventor: James E. Fenton, Ann Arbor, Mich.

[73] Assignee: Ford Motor Company, Dearborn,

Mich.

221 Filed: Dec. 20, 1972 21 Appl. No.2 316,946

[52] US. Cl 60/39.l4, 60/3928 R, 60/3982 R [51] Int. Cl. F02c 7/26 [58] Field of Search 60/39;l4, 39.82

[56] References Cited UNITED STATES PATENTS 5/1968 Ehni 60/3914 R 3,469,395 9/1969 Spitsbergen 60139.14 R 3,470,691 10/1969 Smith 60/3914 R 3,600,887 8/1971 Gault 60/3914 R 3,662,545 5/1972 Davis 60/3914 R 3,686,859 8/1972 White 60/3914 R 3,691,759 9/1972 Seheerer 60/3914 R Primary ExaminerC1arence R. Gordon Assistant ExaminerWarren Olsen Attorney, Agent, or FirmRobert W. Brown [57] ABSTRACT Solid state NOR gates are connected into a logic circuit for controlling, starting and operating a gas turbine engine. The logic circuit requires less electric current and reduces switch costs while increasing overall reliability and life.

5 Claims, 1 Drawing Figure SOLID STATE STARTING AND OPERATING SYSTEM FOR A CONSTANT COMBUSTION ENGINE SUMMARY OF THE INVENTION This invention relates to and is assigned to the assignee of U.S. Pat. No. Gault et al. 3,600,887 and U.S. Pat. Application Fenton et al. Ser. No. 171,228 filed Aug. I2, 1971, now U.S. Pat. No. 3,747,340.

Prior art starting systems for constant combustion en gines typically comprise a plurality of relay actuated switches and pressure and speed sensitive switches that predetermine the starting procedure and also predeter- I mine relighting procedure in case of an engine flameout. Such relays require considerable amounts of electric current and thus represent a significant drain on the self-contained energy source of an automotive vehicle. Certain-of the switches actuatedby the relays are relatively expensive because of the high'amperage requirements and the large number of operating cycles necessary to achieve useful overall lifev of the control system. The switches also are susceptible to momentary failure under mechanical impacts of the type encountered frequently in automotive vehicles; such momentary failure can shut down the entire control system if a switch involved in the failure controls a critical relay that is activated or deactivated improperly by the failure.

The control system provided by this invention uses minimal electric current and simplifies and reduces the cost of its electrical switches. Solidstate logic devices used in the control system have an extremely long useful life and the very low current requirements of the logic devices and the associated switches produces an extremely durable control system. In a constant combustion engine having an ignition system, a starter relay and associated starter motor and a fuel supply system for supplying pressurized fuel to the combustion chamber of the engine, the control system comprises a manual starter switch, a combustion indicating switch for indicating the pressure of combustion within the combustion chamber of the engine, and solid state logic circuitry for controlling the ignition, starting and fuel supply systems.

Solid state logic devices useful in the invention include OR gates, NOR gates, AND gates and NAND gates. Output driver circuits are associated with the logic circuitry to provide necessary current levels for actuating various relays, warning lights and solenoids. A control system using NOR gates is preferred because of reduced cost, low current requirements, and high reliability. Overall current requirements of the control system of this invention using NOR gates, including the current requirements of the driver circuits, is about 0.7 amperes at 12 volts which compares very favorably with the 4.1 amperes required by a comparable prior art system of the relay type.

The combustion indicating switch used in this invention can be a switch operated by the temperature differential system described in U.S. Pat. application Fenton et al. S.N. 171,228, filed Aug. 12, 1971 and assigned to the same assignee, or a switch operated by a light sensing system that responds to the light produced by combustion.

BRIEF DESCRIPTION OF THE DRAWING The drawing is a schematic diagram of a control system of this invention in which the solid state logic cir- 5 cuitry is made up primarily of NOR gates.

DETAILED DESCRIPTION 0 electrical energy source. The positive terminal of battery 10 is connected through a fuse l2 and a conventional automotive ignition switch 13 to a main bus lead 14. A ground lead 16 is connected to the negative terminal of battery 10. Note that ground lead 16 extends down the right side of the drawing, across the bottom and up to the left side just inboard of main lead 14. An electric fuel pump not shown) is connected across battery 10 through switch 13 and is energized whenever electric energy is supplied to main lead 14.

A resistor 18 connects main lead 14 with one input terminal 20 of a solid state NOR gate 22. A fuel pressure sensing switch 24 that is open at fuel pressures below a predetermined value connects terminal 20 to ground lead 16 at fuel pressures above that value. The output terminal of NOR gate 22 is connected through a driver circuit 26 to a parallel connection of a starter relay 28 and starter actuation warning light 30. The starter relay actuates an engine starter motor (not shown).

A resistor 32 connects main lead 14 with one input terminal 34 of a NOR gate 36. The output terminal of NOR gate 36 is connected to an input terminal of a NOR gate 38 and the output terminal of NOR gate 38 is connected to one input terminal of a NOR gate 40.

NOR gate 40 has its output terminal connected to one input terminal of a NOR gate 41 that has its other input terminal 42 connected to ground lead 16 as indicated by the delta. The output terminal of NOR gate 41 is connected to the other input terminal of NOR gate 22. A speed sensing switch 46 that is open above a turbine rotational speed of about l0 percent of design speed closes at lower speeds to connect input terminal 34 of NOR gate 36 to ground lead 16.

A manually actuable starting switch 50 connects main lead 14 with one input terminal of NOR gate 52. The output terminal of NOR gate 52 is connected to an input terminal of NOR gate 36, an input terminal of NOR gate 54, and an input terminal of NOR gate 84. NOR gate 54 has its other input terminal connected directly to ground lead 16. The output terminal of NOR gate 54 is connected to the other input terminal of NOR gate 52 to form a loop arrangement that fixes the output of NOR gate 52 after a momentary actuation of starter switch 50.

One input terminal of a NOR gate 56 is connected to input terminal 34 of NOR gate 36 and its other input terminal is connected directly to ground lead 16. The output terminal of NOR gate 56 is connected to one input terminal of NOR gate 58. A resistor 60 connects another input terminal 62 of NOR gate 58 to main lead 14 and a speed sensing switch 64 that is open above turbine rotational speeds of, about 44 percent of design speed closes at lower speeds to connect terminal 62 to ground lead 16. A resistor 66 connects input terminal 68 of a NOR gate 70 to main lead 14. A switch 72 that is open when no combustion is indicated within the engine closes when such combustion is indicated to con nect input terminal 68 to ground lead 16. The other input terminal of NOR gate 70 is connected directly to ground lead 16 and the output terminal of NOR gate 70 is connected to an input terminal 71 of NOR gate 58.

The remaining input terminal 73 of NOR gate 58 is connected to the output terminal of NOR gate 40. The output terminal of NOR gate 40 is connected to one input terminal of NOR gate 38, to the input terminal of a starter timer 74 to one input terminal of NOR gate 136, and to drivercircuit 43 and air pump relay 44. Starter timer 74 is a commercially available circuit that produces a zero level signal at its output'until the end of a predetermined time period, at which time a one level signal is produced. The time period is initiated by a one level signal at the starter timer input, and its zero level output can be reset or restored by a zero level signal applied to its input. The output terminal of starter timer 74 is connected to an input of NOR gate 76. The output terminal of NOR gate 76 is connected to an input terminal of a NOR gate 78 that has its output terminal connected to the other input terminal to NOR gate 76 to form a loop arrangement like that involving NOR gate 52 and 54. NOR gate 78 also has its output terminal connected to one input terminal of NOR gate 40'and to one input terminal of NOR gate 80.

Another input terminal of NOR gate 40 and another input terminal of NOR gate 80 are connected to input terminal 62 of NOR gate v58; switch 64 when closed thus connects input terminals of NOR gates 40, 58 and 80 to ground lead 16. NOR gate 80 has its output terminal connected to an input terminal of NOR gate 82 and the output terminal of a NOR gate 82 that has its output terminal connected to an input terminal of NOR gate 84. The output terminal of NOR gate 84 is connected to a driver circuit 86 that in turn is connected to a fuel solenoid'88. NOR gate 84 also has its output terminal connected to one input terminal of a NOR gate 90 and NOR gate 90 has its output terminal connected to one input terminal of NOR gate 84 to form another loop arrangement. A single pole, double throw switch has its pole 92 connected to the other input terminal to NOR gate 90. Pole 92 is movable to one terminal 94 that is connected to the output terminal of gate 40 and to another terminal 96. When pole 92 is connected to pole 44 the relight sequence is inhibited. When pole 92 is connected to pole 96 the relight sequence is operational.

The output terminal of NOR gate 58 is connected to the input terminal of a relighting timer 100. Relighting timer 100 is similar in operation to starter timer 74. The output of relighting timer 100 is connected to an input terminal of a NOR gate 102. The output of NOR gate 102 is connected to an input terminal of NOR gate 104 and the output terminal of NOR gate 104 is connected to an input terminal of NOR gate 102 to form a loop arrangement. NOR gate 104 also has its output terminal connected to an input terminal of NOR gate 40 and to NOR gate 80. The other input terminals of NOR gates 78, 82 and 104 are connected to the output terminal of NOR gate 70. NOR gate 70 also has its output terminal connected through a warning light 106 to ground lead 16.

A resistor 108 connects main lead 14 to one input terminal 110 of a NOR gate 112. Terminal 110 is connected through a warning light 114 to ground lead 16. A normally closed switch 116 opens when engine temperature or engine speed exceeds predetermined values to connect terminal to ground lead 16. Terminal 110 also is connected to one input terminal of NOR gate 84. The output terminal of NOR gate 112 is connected to the input terminal of NOR gate 118 and the output of NOR gate 118 is connected to an input terminal of NOR gate 112 to form another loop. NOR gate 118 also has its output terminal connected to one input terminal of NOR gate 84.

Main lead 14 is connected by a resistor 120 to one input terminal 121 of a NOR gate 122. A normally open switch 124 closes in case of an accessory failure to connect input terminal 121 of NOR gate 122 to ground lead'l6. The other input terminal of NOR gate 122 is connected directly to ground lead 16 and the output terminal of NOR gate 122 is connected to an input terminal of NOR gate 84. NOR gate 118 has its other input terminal connected to input terminal 62 of NOR gate 58. NOR gate 126' has one input terminal connected to terminal 62 and its other input terminal connected directly to ground lead 16. The output terminal of NOR gate 126 is connected through a driver circuit 128 and a diode 130 to an ignition system 132. It is also connected to terminal 96 and to driver circuit 142 and indicating light 144.

A resistor 134 connects main lead 14 to one input terminal 135 of a NOR gate 136. A normally open switch 138 closes under either low oil pressure or high oil temperature to connect terminal 135 of NOR gate 136 to ground lead 16. A warning light 140 also connects terminal 135 to ground lead 16. The output terminal of NOR gate 136 is connected to the last remaining input terminal of NOR gate 84.

OPERATION The NOR gates of the control circuit of this invention are binary logic devices in that the gates consider only the two levels of electric potential which can be designated as a zero level and a one level. A zero level corresponds to the potential in ground lead 16 and a one level corresponds to a potential of something less than the main bus lead 14. A one at any input terminal of a NOR gate produces the zero at its output terminal. If all input terminals of a NOR gate are at the zero level, the NOR gate output terminal is at a one level. Resistors 18, 32, 60, 66, 108, 120 and 134 typically are about 1,000 ohms. Each resistor is associated with a switch that closes to connect the resistor to ground lead 16, i.e., switch 24 is associated with resistor 18, etc. When its associated switch is open, the resistor applies a voltage of main lead 14 to the input terminal of the NOR gate to which the resistor is connected and thereby produces a one at that input terminal. Closing the switch associated with the resistor, reduces the voltage level at that input terminal to a zero.

In the description which follows, the input terminals to the various NOR gates are referred to as the first input, second input, etc. The first input is the one uppermost in the drawing, the second is the next one down from the first, and so forth.

A starting sequence for the gas turbine engine occurs in the following manner. The engine operator closes momentarily the manual start switch 50 and thereby applies a one to one input terminal of NOR gate 52. NOR gate 52 produces zero at its output terminal, NOR gate 54 then has a zero at each of its input terminals and it therefore produces a one at its output terminal. The one from the output terminal of NOR gate 54 is applied to the other input terminal of NOR gate 52 and thereby locks NOR gate 52 into a condition where the output'of NOR gate 52 remains at a zero level.

Since the turbine is at rest, speed sensing switch 46 is closed and a zero appears at each input terminal of NOR gate 36. NOR gate 36 produces a one at one input terminal of NOR gate 38 and NOR gate 38 in turn applies a zero to one input terminal of NOR gate 40. Speed sensing switch 64 is closed to apply a zero to the second input terminal of NOR gate '40. The starter timer 74 has a zero output that appears at the first input terminal of NOR gate 76. The other terminal of NOR gate 76 also is at the zero level so that NOR gate 76 applies a one to the input of NOR gate 78. NOR gate 78 in turn applies a zero to the third input terminal of NOR gate 40. Similarly, since the switch within relighting timer 100 is open, zeros appear at each input terminal of NOR gate 102 which applies a one to one input terminal of NOR gate 104. NOR gate 104 thus applies a zero to the fourth and last input terminal of NOR gate 40. Since each of its input terminals is at a zero level, NOR gate 40 produces a one at-its output terminal to activate driver circuit 43 and thereby activate air pump relay 44.

A fuel pressure sensing switch 24 closes when fuel pressure at the injection nozzle within the combustion chamber reaches a predetermined minimum value and thereby applies a zero to terminal of NOR gate 22. The one at the output terminal of NOR gate 40 is applied to one input terminal of NOR gate 41 which applies a zero to the other input terminal of NOR gate 22. NOR gate 22 thus has a zero at each input terminal and it applies a one to driver circuit 26. Driver circuit 26 energizes starter relay 28 and warning light 30. (Note that closed switch 64 applies a zero to one terminal of NOR gate 126 which always has a zero applied to its other input terminal so that NOR gate 126 applies a one to driver circuit 128 to energize ignition system 132 and to driver circuit 142 to energize indicating light 144.) 1

Fuel solenoid 88 is open by virtue of the following sequence. The one level at the output of NOR gate 126 is applied through terminal 96 and switch pole 92 to the second input terminal of NOR gate 90. NOR gate 90 thus applies a zero to the first input of NOR gate 84. NOR gate 52 has its output locked at zero level to apply a zero to the second input terminal of NOR gate 84. The third input to NOR gate 84 is a zero because it is the output of NOR gate 82, which has a one on its first input as a result of zeros applied to the three inputs of NOR gate 80. These three zero inputs to NOR gate 80 are the zero output of NOR gate 78, the zero output of NOR gate 104, and the zero level signal from speed sensing switch 64. The fourth input to NOR gate 84 is a zero level signal obtained from the normally closed high temperature/high speed switch 116. The fifth input to NOR gate 84 is a zero output obtained from NOR gate 118. The NOR gate 118 output is a zero because its first input is a one obtained as the output of NOR gate 112, which has the zero from switch 116 on its first input and has the zero of NOR gate 118 on its second input. NOR gate 122 has a zero output because a one is applied to its first input from accessory switch 124, in the absence of an accessory failure. The zero output of NOR gate 122 is the sixth input to NOR gate 84. The seventh input to NOR gate 84 is a zero obtained as the output of NOR gate 136, which has the output one of NOR gate 40 applied to its first input.

In summary of the above operation description. the momentary depression of starting switch 50 energizes the starter relay 28, the air pump relay 44, the ignition system 132, and opens the fuel solenoid 88. Also, the one signal of NOR gate 40 is applied to the starter timer 74 to cause it to initiate a time interval, such as 5 seconds, at the end of which time a one signal occurs at its output and is applied to the first input of NOR gate 76.

Combustion is indicated by the closure of switch 72. This applies a zero to the first input of NOR gate and, because its second input is always zero, the output of NOR gate 70 changes from a zero to a one. The one output signal of NOR gate 70 is applied to the respective second inputs of NOR gates 78, 82 and 104 to inhibit changes in their zero level outputs. Thus, when the starter timer 74 times out to apply a one to the first input to NOR gate 76 to change its output to a zero, the output of NOR gate 78 remains a zero. Similarly, the outputs of NOR gates 104 and 82 remain zeros.

The occurrence of combustion allows the engine to accelerate. When the engine speed reaches about 10 percent of design speed, speed sensing switch 46 opens applying a one to the first inputs of NOR gates 36 and 56. The outputs of these gates become zeros. Also, at engine speeds above about 44 percent of design speed, the speed sensing switch 64 opens applying a one signal to the second input of NOR gate 40. This causes the output of NOR gate 40 to become a zero which, in turn, de-energizes driver circuit 43 and air pump relay 44 and applies a zero to the second input of NOR gate 41 to change its output to a one. The one output of NOR gate 41 is applied to the second input of NOR gate 22, changes its output to a zero, and this de-energizes starter relay 28. The one signal obtained when speed sensing switch 64 opens also is applied to the first input of NOR gate 126. This changes its output to a zero, deenergizing the driver circuit 128 for ignition system 132 and the driver circuit 142 for indicating light 144.

Let it now be assumed that the engine starting sequence has been initiated by the momentary depression of starting switch 50 but that combustion is not sensed by the combustion indicating device. This means that the combustion indicating switch 72 does not close. Thus, after about five seconds, a one signal appears at the output of starter timer 74 and is applied to the first input of NOR gate 76. The output of NOR gate 76 becomes a zero that is applied to the first input of NOR gate 78. The second input of NOR gate 78 is also a zero because this input is obtained from the output of NOR gate 70, which has the one of the combustion indicating switch 72 applied to its first input. Therefore, the output of NOR gate 78 is a one. This signal is applied to NOR gate 80, the output of which changes to a zero. The zero output of NOR gate 80 is applied to the first input of NOR gate 82 and the second input to NOR gate 82 is the zero output from NOR gate 70. As a result, the output of NOR gate 82 is a one that is applied to the third input of NOR gate 84. The output of NOR gate 84 becomes a zero and the driver circuit 86 for fuel solenoid 88 is de-energized closing the fuel valve. It should be noted that the one signal at the output of NOR gate 78 is applied to the third input to NOR gate 40 producing a zero at its output. A zero at this point de-energizes the starter relay 28 and air pump relay 44 in the manner previously described.

Let it now be assumed that a normal engine start has occurred and that the engine has reached an idle speed of about 55 percent of engine design speed, but that a flame-out (cessation of combustion) subsequently occurs. In such case, the speed sensing switches 46 and 64 both will have opened prior to the engine having reached idle speed. At this time, starter timer 100 has a zero level signal at its output because it has been reset by a zero applied to its input from the output of NOR gate 40. Thus, NOR gate 76 has a zero at both of its inputs and produces a one at its output. Combustion indicating switch 72 opens when combustion is no longer detected. A zero appears at the output ofNOR gate 70 and is applied to the fourth input of NOR gate 58 and to the second inputs of NOR gates 78, 82 and 104. The output of NOR gate 78 remains a zero and this is applied to the first input of NOR gate 80. Because speed sensing switch 64 is open, a one from it is applied to the third input of NOR gate 80. The result is a zero at the output of NOR gate 80, and this zero is applied to the first input of NOR gate 82. Therefore, the application of the above-mentioned zero to the second input of NOR gate 82 when a flame-out occurs produces a one at its output that is applied to the third input of NOR gate'84. This drives the output of NOR gate 84 to a zero and de-energizes the driver circuit 86 for fuel solenoid 88 to stop fuel flow. The zero output of NOR gate 84 is applied to the first input of NOR gate 90. Because the second input to NOR gate 90 is a zero obtained from NOR gate 126, the output of NOR gate 90 is a one that is applied to the first input of NOR gate 84 to latch its output to a zero.

At the time of engine flame-out, a zero is present at the output of NOR gate 40 and is applied to the first input of NOR gate 58. The second input to NOR gate 58 is a zero obtained from the output of NOR gate 56 which, in turn, is controlled by speed sensing switch 46. The fourth input to NOR gate 58 also is a zero as a result of the previously mentioned opening of combustion indicating switch 72. Only the third input of NOR gate 58 has a one signal applied to it, this being due to "the open condition of speed sensing switch 64. However, the occurrence of the flame-out causes the engine speed to decrease to a point at which speed sensing switch 64 closes. A zero is applied to the third input of NOR gate 58, a one is produced at its output, and the relighting timer 100 is started. lts output changes from a zero to a one at the end of the timed interval. At the same instant the relighting time is initiated, the zero produced by the closure of speed sensing switch 64 is applied to the first input of NOR gate 126, which results in a one signal at its output that energizes the driver circuit 128 for the ignition system 132. The zero produced by the closure of speed sensing switch 64 also is applied to the third input of NOR gate 80, which then has zeros on all of its inputs and produces a one at its output. A one on the output of NOR gate 80 results in a zero at the output of NOR gate 82 that is applied to the third input of NOR gate 84. Also, the one output of NOR gate 126 used to energize the ignition system is applied to the second input of NOR gate 90. Note that if movable pole 92 is connected to terminal 94 then the second input to NOR gate 90 is at zero and the relight sequence is inhibited. The output of NOR gate 90 becomes a zero applied to the first input of NOR gate 84. At this moment, all of the inputs to NOR gate 84 are zeros, its output becomes a one, and the driver circuit 86 for fuel solenoid 88 is energized once again to supply fuel to the engine.

If the above-described attempt to achieve relighting by actuation of the ignition system and re-supply of fuel is successful, this is indicated by the closure of combustion indicating switch 72. Closure of this switch produces a one at the output of NOR gate 70. The one output of NOR gate is applied to the second inputs of NOR gates 78, 82 and 104 thereby maintaining their output signals at the zero level. With the output of NOR gate 82 at zero, fuel continues to be supplied to the engine. Also, when a one appears at the output of the relighting timer 100, there is no effect on the output of NOR gate 104. The engine accelerates to a speed in excess of that at which speed sensing switch 64 opens. The opening of speed sensing switch 64 results in the application of a one to the first input of NOR gate 126 to produce a zero at its output and to de-energize the driver circuit 128 for the ignition system 132.

If the relighting timer 100 times out before combustion is restored, the one then produced at its output is applied to the first input of NOR gate 102, changing its output to a zero, and the output of NOR gate 104, thus having two zero inputs, becomes a one. The one output of NOR gate 104 is applied to the second input of NOR gate changing its output to a zero. This changes the output ofNOR gate 82 to a one which, in turn, changes the output of NOR gate 84 to a zero de-energizing the driver circuit 86 for the fuel solenoid 88.

The control circuit includes several switch inputs that are used in the event of engine malfunctions to apply,

directly or indirectly, one level signals to inputs of NOR gate 84. A one at any of these inputs produces a zero at the output of NOR gate 84 which de-energizes the driver circuit 86 for fuel solenoid 88. In the case of switch 116, either excessive engine temperature or speed causes this switch to open and a one signal then is applied directly to the fourth input of NOR gate 84. If an engine accessory fails, switch 124 closes applying a zero to the first input of NOR gate 122, and, because a zero exists at all times on its other input, a one is produced at its output. This one signal is applied to the sixth input of NOR gate 84. With respect to switch 138, either low oil pressure or high oil temperature cause it to close. This applies a zero to the second input to NOR gate 136. The first input to NOR gate 136 also is a zero except when NOR gate 40 produces a one at its output during the engine starting sequence). Thus, a one results at the output of NOR gate 136 and is applied to the seventh input to NOR gate 84.

Based upon the foregoing description of the invention, what is claimed is:.'

1. A starting and operating system for a constant combustion engine having a starter motor and a driver circuit for said starter motor, having means for discharging fuel into a combustion chamber of said engine and a driver circuit for said fuel discharge means, and having an ignition system for igniting fuel discharged into said combustion chamber and a driver circuit for said ignition system, said constant combustion engine starting and operating system comprising, in combination:

an engine starting switch;

means for indicating combustion in said combustion chamber;

means for sensing whether the speed of said engine is above or below a first predetermined level;

means for sensing whether the speed of said engine is above or below a second predetermined level;

NOR gate logic circuit means for energizing said starter motor driver circuit, said fuel discharge means driver circuit, and said ignition system driver circuit when said starting switch is actuated and the speed of said engine is below said first predetermined level;

NOR gate logic circuit means for de-energizing said starter motor driver circuit and said ignition system driver circuit when the speed of said engine exceeds said second predetermined level;

NOR gate logic circuit means for de-energizing said starter motor driver circuit, said fuel discharge means driver circuit and said ignition system driver a circuit if said combustion indicating means does not indicate combustion at the end of a predetermined time interval initiated by actuation of said starting switch; and

NOR gate logic circuit means for de-energizing said fuel discharge means driver circuit if said combustion indicating means does not indicate combustion when the speed of said engine exceeds said second predetermined level.

2. A starting and operating system for a constant combustion engine in accordance with claim 1, said system further comprising solid state relighting circuit means including NOR gate logic circuitry for energizing said fuel discharge means driver circuit and said ignition system driver circuit when the speed of said engine exceeds said first predetermined level and said combustion indicating means does not indicate combustion.

3. A starting and operating system for a constant combustion engine in accordance with claim 1, said system further comprising solid state relighting circuit means including NOR gate logic circuitry for energizing said fuel discharge means driver circuit and said ignition system driver circuit when the speed of said engine is below said second predetermined level and said combustion indicating means does not indicate combustion.

4. A starting and operating system for a constant combustion engine in accordance with claim 2, said system further comprising circuit means including NOR gate logic circuitry for limiting the energization of said fuel discharge means driver circuit and said ignition system driver circuit, when the speed of said engine exceeds said first predetermined level and said combustion indicating means does not indicate combustion, to a predetermined time interval.

5. A starting and operating system for a constant combustion engine in accordance with claim 3, said system further comprising circuit means including NOR gate logic circuitry for limiting the energization of said fuel discharge means driver circuit and said ignition system driver circuit, when the speed of said engine is below said second predetermined level and said combustion indicating means does not indicate combustion, to a predetermined time interval. 

1. A starting and operating system for a constant combustion engine having a starter motor and a driver circuit for said starter motor, having means for discharging fuel into a combustion chamber of said engine and a driver circuit for said fuel discharge means, and having an ignition system for igniting fuel discharged into said combustion chamber and a driver circuit for said ignition system, said constant combustion engine starting and operating system comprising, in combination: an engine starting switch; means for indicating combustion in said combustion chamber; means for sensing whether the speed of said engine is above or below a first predetermined level; means for sensing whether the speed of said engine is above or below a second predetermined level; NOR gate logic circuit means for energizing said starter motor driver circuit, said fuel discharge means driver circuit, and said ignition system driver circuit when said starting switch is actuated and the speed of said engine is below said first predetermined level; NOR gate logic circuit means for de-energizing said starter motor driver circuit and said ignition system driver circuit when the speed of said engine exceeds said second predetermined level; NOR gate logic circuit means for de-energizing said starter motor driver circuit, said fuel discharge means driver circuit and said ignition system driver circuit if said combustion indicating means does not indicate combustion at the end of a predetermined time interval initiated by actuation of said starting switch; and NOR gate logic circuit means for de-energizing said fuel discharge means driver circuit if said combustion indicating means does not indicate combustion when the speed of said engine exceeds said second predetermined level.
 2. A starting and operating system for a constant combustion engine in accordance with claim 1, said system further comprising solid state relighting circuit means including NOR gate logic circuitry for energizing said fuel discharge means driver circuit and said ignition system driver circuit when the speed of said engine exceeds said first predetermined level and said combustion indicating means does not indicate combustion.
 3. A starting and operating system for a constant combustion engine in accordance with claim 1, said system further comprising solid state relighting circuit means including NOR gate logic circuitry for energizing said fuel discharge means driver circuit and said ignition system driver circuit when the speed of said engine is below said second predetermined level and said combustion indicating means does not indicate combustion.
 4. A starting and operating system for a constant combustion engine in accordance with claim 2, said system further comprising circuit means including NOR gate logic circuitry for limiting the energization of said fuel discharge means driver circuit and said ignition system driver circuit, when the speed of said engine exceeds said first predetermined level and said combustion indicating means does not indicate combustion, to a predetermined time interval.
 5. A starting and operating system for a constant combustion engine in accordance with claim 3, said system further comprising circuit means including NOR gate logic circuitry for limiting the energization of said fuel discharge means driver circuit and said ignition system driver circuit, when the speed of said engine is below said second predetermined level and said combustion indicating means does not indicate combustion, to a predetermined time interval. 